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Yeah. Set it back to SD and log fuel trims.
Should be getting misfire with a wiped lobe.
I saw a problem one time on a SBC where oil pressure dropped when a lifter was at a certain spot. Noticed it while running the oil pump with an electric drill and turning the motor over with a wrench. Block had to get bronze lifter bushings.
This post has a few applicable ideas. Didn't you mention something about a hole drilled into a galley plug?
https://www.speed-talk.com/forum/viewtopic.php?t=47909
Alright back from vacation. How are you doing?
Here's something else I found:
https://www.camaros.net/threads/dril...-plugs.452329/
"I was a GM service technician back in the 70's and GM sent a bulliten out around 1970, that was the year that they revamped the Mark IV engine, stating that all of these big blocks now have the front gallery plugs drilled. The sole purpose of this, according to GM, was to bleed off the tiny air bubbles trapped in the lifters. This condition was more prominent when a higher lift cam was installed with stronger valve springs. This air being trapped in the lifters could happen to any given lifter, but was more prominent in the forward lifters due to the fact that the longer distance to the front of the engine made it harder for the lifters to bleed out. This condition usually happened after a drive, causing the oil to become thinner, stopping the engine when the front valves are in their open position. The pressure from the spring is higher due to the valve being open. While the engine is shut off, the spring pressure would put pressure on the hydraulic lifter plunger, thus collapsing it. The bonus of drilling these plugs is that you provide extra oil to the timing gear set. Most engine rebuilders have no idea of this and therefore do not drill these holes."
Good! Had a mini-vacation before my real vacation. We took a trip to VA beach for a graduation present concert for my daughter. Was fun. I put that QS Euro in and it seemed louder actually. I didn't yet drive it or even look at anything since then. I am wondering if maybe my valve adjustment process left them a little loose all around. I had read some threads that said 'wiggle the pushrods till there is no up/down movement then do a 1/2 turn'. I also read 'rotate the pushrods till they don't spin, then do 3/4 turn'. So I had done the wiggle till no up/down play, then 3/4 turn... Maybe my definition of play and the real definition of play is different? I contacted CompCams and they mentioned that, for those lifters, between 3/4 and 1-1/2 turns was good, with ideal at 1 turn... I am going to go another 1/2 turn on one side to see if it makes a difference and if it does then I will do the other side. I will also check the geometry and the roller tip where it hits the valve tip to look for wear or deformation... I was a little concerned when I drained the second batch of oil and it still had the swirl and 'glitter' in it, but read on a lot of places that the first few oil changes can do that. Nothing big in there, just a bit of sparkle at night with a flashlight. When draining the oil it looks clear, I just can see the swirl in the pan and the magnetic drain plug was basically just discolored, not the porcupine looking pattern. It was a full rebuild with new bores, rings, pistons, crank, rods, cam, cam bearings, lifters, pushrods, rockers, springs, rocker studs, timing chain, and oil pump, so I could see some normal wear/break-in occurring? No knocking, just lifter/rocker noise. I've seen the bearing slop oil recently when I took it apart and it doesn't seem like that at all. I am probably just trying to talk myself down though! :)
Congrats! You must be a proud dad.
I always did pushrods until I couldn't rotate by fingertips. Then lock them down 1 1/2 or so.
Have to be careful because doing it this way with a collapsed lifter will lead to bad results. I think what you're dealing with is as described above. Air ingress and high spring pressure. I'd be wary of adjusting the lifters without taking into consideration that they may already near bottom. It's a simple procedure but easy to screw up.
What do you think about the comments concerning the gallery plugs being drilled? Sounds about right, especially considering the pronounced effects with lighter grade oil. Think you need to pull the timing cover and do that? I read GM spec is a .030" hole, but I've seen a lot of people doing a .020" hole in the plug for each lifter bank located right behind the timing sprocket.
Thanks! I am! So that twist feel on the pushrods is on a hydraulic lifter too? I wasn't sure about that part and did think that I may have erred on the waaaaayyyy loose side of things as I just took out what I could feel in up/down play. The rods still spun and moved around side to side, but not up/down. I.E. I could shake the rocker arm around side to side. I am not sure that the drilled plug applies to the Gen VI block as it has its own main for the cam and for the crank mains as far as oil galley is concerned? I did hear of it in the Mark IV, but not the Gen VI... I know the builder didn't seem concerned when I told him I removed it after having put it in the rear of the engine by mistake. I would also expect the small bubble bleed out to be an intermittent thing no? I am going away next week on vacation and then going away for work the week after so between the packing and prep work, I will try to get something done! :) I was second guessing myself about the looseness of the pushrods to begin with so I'll definitely try to take a long hard look at that and the geometry/pattern before I go.
Yes, that's what to do on these hydraulic lifters. When the pushrod stops spinning by light finger pressure that means there is no gap between the pushrod and the lifter cup and rocker arm. Once that is reached THEN preload is set by turning the rocker nut a set amount. Of course, this is assuming that the lifter isn't collapsed. That's what to look out for. So, loosen the rocker arm until there is a lot of play. Give the lifter time to raise the plunger back to the top of travel. Also, I prefer to do adjustment when the lifter is riding on the base circle of the cam. This means both valves are closed on the cylinder being adjusted, somewhere between the compression and expansion strokes - intake valve closes then give a half turn on the crank. Make sure the pushrod is seated where it's supposed to be when setting preload. Don't get it off-center.
If 1 1/2 turn preload was applied to solid lifters then that would be very bad. Valves would hang open, and something would have to give eventually.
As far as air in the lifters, I too figured that the air should bleed itself out. Thing is it doesn't for some reason. GM saw fit to add the holes on Gen IV. I was under the impression that this meant Gen IV and up. Maybe there was an oiling revision on VI that means this is no longer required? I haven't seen evidence for that. Oil passages were revised in Gen V to move the lifter passage closer to the cam, but the circuit is still the same as IV. If you look at the different block versions the plug locations change slightly, but they're still there.
What stood out in the comments is that lifter collapse is made worse by higher lift cams and stronger valve springs, which is exactly your setup.
Putting in drilled plugs will remove one (likely) variable. Plus, extra lube on the timing set will help longevity. If the valvetrain noise can't be adjusted out I recommend trying it.
Different manufacturers have different specs on lifter preload. Call and find out what they recommend.
LS rocker bolt is an 8mm x 1.25 = 20.32 threads per inch
1”/ 20.32 = .0492 trunnion movement per turn of the rocker retainer
.0492 applied to appropriate formula =.078 lifter preload per turn for a (1.7) rocker
.0492 applied to appropriate formula =.076 lifter preload per turn for a (1.8) rocker
Typically If the bolt rotates 1 1/4 turns after a zero lash, you would want a pushrod that is .025” shorter than stock
If the bolt rotates 1/2 turn, you would want a pushrod that is .025” longer than stock
Right, but this is a different setup than LS. It's a BBC. No rocker bolts to lock down. No trunnions. Preload is set with the rocker nuts, not by changing pushrod length.
Take a look at the parts list on Post #60.
There is an instance here where changing to different length pushrods would be warranted. Once preloaded wear pattern on the valve tip must be checked. If it's too far off center then a different length will need to be selected. It can be hard to judge the contact pattern with roller tips. Put permanent marker on the valve tip and see where it wipes away. Due to the rollers, might have to wiggle the rocker side to side while rotating the engine over a few times to get it to wipe away.
It's tedious stuff. Don't be in a hurry. Pick a good few hours where you really don't need to be doing anything else. Otherwise you'll get pretty pissed off lol.
That reminds me. I used the TDC wiggle/tighten all, spin 1/4 turn, wiggle/tighten, repeat for 2 full revolutions. Then I did the preload. From first start till now, the noise has been pretty consistent as in initially I thought the lifters didn't pump up because I didn't soak them, but it never changed. The Oil is at 60 PSI cold, no matter what viscosity and then will lower to about 18-20 PSI when IATs are like 130-140 and the Gauge reads 200-210. Jumps immediately when goosed and will sit at between 40-45 at 1800-2500 RPM. The Gen VI does have a separate galley for the Main Crank Bearings AND a separate galley for the Camshaft (Called Priority Main). I also found differences in the clocking of the cam bearings. I was following what I found and noticed that I was effectively told to block off the oil hole if I used the "454" cam bearing info. Turns out that the cam bearing clocking is different on the gen VI as well. I am pretty sure if I got that wrong I wouldn't have 600-700 miles on the cam without something going south by now eah?Quote:
Originally Posted by SiriusC1024
Basic formula is no different. BBC are 14 TPI. Manufacturers will usually call out the depth.Quote:
Originally Posted by SiriusC1024
As to the tighten spin method that is a big no. Lash must be set ONLY at base circle.
Small and Big Block Chevy, and other engines using the 1-8-4-3-6-5-7-2 firing order. is it easy to understand?A more detailed explanation follows below the chart. For other engines, use the firing order that matches the engine to create a similar chart.
Intake Valve Adjustment:
with #1 cylinder Intake Valve at full valve lift …. Adjust #6 Intake Valve
with #8 cylinder Intake Valve at full valve lift …. Adjust #5 Intake Valve
with #4 cylinder Intake Valve at full valve lift …. Adjust #7 Intake Valve
with #3 cylinder Intake Valve at full valve lift …. Adjust #2 Intake Valve
with #6 cylinder Intake Valve at full valve lift …. Adjust #1 Intake Valve
with #5 cylinder Intake Valve at full valve lift …. Adjust #8 Intake Valve
with #7 cylinder Intake Valve at full valve lift …. Adjust #4 Intake Valve
with #2 cylinder Intake Valve at full valve lift …. Adjust #3 Intake Valve
Exhaust Valve Adjustment:
It is obvious that this is the same procedure and sequence as the intake valves listed above. This time, ONLY the exhaust valves are being adjusted.
with #1 cylinder Exhaust Valve at full valve lift …. Adjust #6 Exhaust Valve
with #8 cylinder Exhaust Valve at full valve lift …. Adjust #5 Exhaust Valve
with #4 cylinder Exhaust Valve at full valve lift …. Adjust #7 Exhaust Valve
with #3 cylinder Exhaust Valve at full valve lift …. Adjust #2 Exhaust Valve
with #6 cylinder Exhaust Valve at full valve lift …. Adjust #1 Exhaust Valve
with #5 cylinder Exhaust Valve at full valve lift …. Adjust #8 Exhaust Valve
with #7 cylinder Exhaust Valve at full valve lift …. Adjust #4 Exhaust Valve
with #2 cylinder Exhaust Valve at full valve lift …. Adjust #3 Exhaust Valve
In the instructions above, adjustments are being made on the “opposite” valves in the firing order, specified by the engine rotation cycle. The example shows an engine with the firing order of 1-8-4-3-6-5-7-2. It is these opposites that position the opposing valve at the correct location for adjustment. That proper location is when the lifter resides on the back side (base circle, or heel) of the cam lobe, meaning that the valve is in the fully closed position.
Please, DO NOT try to adjust both intake and exhaust valves at the same time. It is NOT accurate, and gets back to the original request of forgetting (or ignoring) what was previously known about valve adjustment procedures. Each valve is adjusted independently. That means specifically, that sixteen (16) individual adjustments will occur on a typical V8 engine.
I will give that a go as soon as I can find the time. I am going away this weekend thru next weekend and then traveling for business the following week! Sheesh.... Thanks for the info. The wiggle/tighten did get it running for me though! :) I will let it sit till I can do it right. Thanks!
Look. I get you're trying to help. That order of operations is an alternative way to get to base circle, but you're confusing the situation.
Most definitely use the spin method to find zero lash. After that apply preload.
The preload as measured in thousandths in relation to thread pitch and turns has already been figured. There is no 'if bolt turns this far after zero lash then get a different pushrod length' about it. The nut is supposed to be turned after zero lash. That's how the lifter is preloaded. Again, you're talking about LS-style trunnions or shaft-mount rockers like on a 340 Mopar. These don't work that way.
Do it on the base circle. I already said that.
Certainly, both rockers on a cylinder can be adjusted at the same time. If it's done as I described then both are on the base circle. This happens midway between compression and expansion strokes. BOTH VALVES ARE FULLY CLOSED.
There are 3 ways to make sure that the lifter is on the base circle:
1 - Turn engine over until intake valve closes. Give another half turn on the crank.
2 - Method based on firing order
3 - The best method. Use a dial indicator. Indicate on the valve spring retainer.
Follow my instructions:
- Cold engine
- Select a cylinder for adjustment
- Choose a method for getting the lifter on the base circle of the cam.
- Loosen rocker nut and let lifters relax
- Tighten rocker nut until pushrod can't be spun with finger pressure.
- Tighten rocker nut to set preload (3/4 to 1 1/2 turn. I think it was mentioned that Comp recommends 1 1/4 turn)
- Move on to the next.
Look up any procedure. It's as I described. Here's one:
https://www.speedwaymotors.com/the-t...-8-steps/28654
As far as checking valve tip contact pattern. This will only need to be done on one rocker because the geometry will be the same for the rest:
- Select a rocker and valve
- Dissassemble. Clean oil of rocker roller tip and valve tip. Apply permanent marker to valve tip.
- Reassemble.
- Set valve lash.
- Turn engine over a few times.
- Check wear pattern.
- If wear pattern is off-center then select a different length pushrod.
I am back! Ugh, what fun business travel is... </sarc> :)
I took the valve covers off and re-adjusted the valvetrain, using my new remote start switch to speed up the engine rotation. I have almost the identical noise. I did notice that the Euro oil caused the noise to increase, so I did swap in the thicker 15W-40 Rotella which seemed to quiet it down somewhat. There was ZERO glitter in the oil this time, but it had maybe a mile on it? The assembly lube 'swirl' was also greatly decreased. Still no metal parts, chunks, slivers, etc. I did notice that if I took the rockers and wiggled them I seemed to be able to recreate the valve noise. Maybe I am hearing the roller tips slapping back and forth or the pushrods gliding on the guides? I will take it apart again tomorrow to see what I can find along the lines of the pushrod guides, the rocker tip geometry or something. I plan to re-run tune 8 now that I have the IATs somewhat reduced to see if you notice any difference? Thanks again for all the help.
Yessir bring it on.
Here are a couple of driving around town logs... after hot soak, the IATs were up, but did seem to come down a bit after driving, but still showed red. I didn't hit the highway or anything so it didn't have a chance to get a lot of cool air. I was thinking of putting in some 102+ octane boost or something to see if we can determine if the knock is real or if it is the valve train noise?
Try the octane booster. There's actually more knock sensor activity than ever.
Did you ever try a quick swap to the factory rockers?
I don't think I had the Knock Sensor logging on last time I ran the #8 tune, but I could be mistaken. Anyway, I got the booster and will get it in tonight and hope to run around a bit tomorrow for some more logs. I like the "quick swap to factory rockers" :) I have the adjustable stud kit and the rollers, but I did have that on the list of things to try with the noise. I don't mind the noise if it is to be expected and we can tune the Knock Sensor out of the picture for the valve train. Is it possible that loud exhaust may contribute to the knock reading as well? I know it had loud exhaust before the new cam and it was raspy before, but now it is off the hook. This has no crossover or H pipe so it is crackly.Quote:
Originally Posted by SiriusC1024
The valvetrain noise is a real pain isn't it? So many things it could be. It's probably something to do with the lifters if it gets quieter with thicker oil. Lifter noise from lash/preload is ruled out after you readjusted. I still think that putting drilled galley plugs in would work be the solution. Suggested rockers because that would handle the pushrod contact on the guides.
Loud exhaust won't affect the knock sensors.
Difference in tune between 8 and when you were logging wouldn't affect the knock activity like that. Spark hasn't been advanced.
If I tune the knock out by desensitizing the sensors then there's no guarantee real knock will be detected.
I probably didn't say what I meant correctly. The tune 8 that I ran logs on the first time didn't have the knock enabled. I went back and looked and it came into play with tune 9. I ran that one both without the KR and then again with the KR. I was hoping that I didn't overdo it with the compression. There was a lot of inconsistent information on calculating the actual compression ratio. I was shooting for 9:1 - 9.5:1 but may have overshot. I do feel it is pretty high due to the herculean effort to crank over by hand! If I need to run high octane with some octane boost, so be it. This is just my tow vehicle a couple times a year and as long as it can tow RELIABLY I am happy! IF the contact pattern looks good without needing adjustable pushrod guides or different length pushrods then I will give the stock rockers a go. IF THAT quiets it down, then I will swap back and run it. I don't mind the noise, I just want to make sure it isn't a symptom of impending engine failure. I want to make sure I am not researching to corroborate the least serious diagnosis and then have that be wrong!Quote:
Originally Posted by SiriusC1024
Let's see how it does with the octane booster.
Funny how something that makes gasoline less aggressive creates more power! :)Quote:
Originally Posted by SiriusC1024
Ok, added two cans (treat 25 gallons each) to my 42 gallon tank, idled for 12 minutes, let sit overnight and then ran it this afternoon out to the store and back.Quote:
Originally Posted by oldpartsnrust
Here are the logs.... I still see knock, but didn't look close enough to see if there is a difference or not.
No difference with the octane booster.
Well. Here's with knock sensors disabled. There's no sensitivity adjustment for the sensors. All you can do is adjust how much spark is removed when knock is detected. Might as well pull it all since who knows what's actual knock.
I'd assume the spark table safe if this was a regular 454. On one hand you've increased displacement through overbore, but on the other hand there is better quench. DCR decreased due to cam. Is that enough? Was hoping to find optimum through tuning.
I don't like doing it this way. If it were me I would have already put in the drilled gallery plugs, used Morel lifters, checked rocker contact, or whatever it took to get the noise to stop. I have doubts about the longevity of the engine.
Changes applied to tune 9. Logs from 9 have more accurate fuel trims. WOT shift RPM and PE adjusted also.
Yeah, I haven't been driving it and the 'day job' which is also a night job gets in the way... Also, I don't have a garage, so the 90+ temps have been slowing me down a bit too. The noise has been constant and consistent. I will be pulling the valve covers and checking the valve contact shortly. I put a few miles on it for the beginning tunes, but have just really been driving it to get logs so that is the only real time on the motor so far. What I read is that the priority main motor (Gen VI) don't need the drilled plugs. The roller lifters aren't cheap and the ones in there right now are new from Comp that came with the kit. It is decked so maybe the contact is a little off and I may need to do something there. I should know in the next day or two. I may put the factory rockers on one side for a few seconds just to test the noise. Lucky for me I am a pack rat and haven't thrown anything away yet. Not even the OEM crank with all its damage. I have to put exhaust on my daily driver before I take this back down (Not available in an emergency) and once I get that done I can dig in.
Attachment 135889
Attachment 135890
Attachment 135891
ok, so I finally got the adjustable pushrod guides so dug in there. I did see a few that weren't perfectly centered. Can that make the noise I am hearing? I didn't know I would need to adjust that as the stock guides had very tight clearance on the holes and the guides don't adjust. Here are some pics of the valvetrain. I think it looks pretty good as far as i don't see any metal or discolored stuff. I do see some of the rollers are not perfectly in the middle of the valve so I am adjusting them and then will reset the preload tomorrow. I was going to put the stock rockers back in but the rocker balls have a larger diameter and they would flop around on the adjustable studs. If I can find the stock bolts I may still do that. Here are the pics of the valvetrain.
It could very well be contact between the pushrods and the guides causing the noise. It's reasonable to assume more deflection at higher rpm. Could always put some permanent marker on the pushrods then run it to see if any scrapes away. Easier than modifying the guides as a test.
The rocker is off-center, but not the way I was talking about. Contact pattern is normally a concern in the direction across the head, intake to exhaust, rather than along the head. I don't see from any of the pictures how the longitudinal offset shown in the picture can be adjusted. That misalignment will translate to the other side of the rocker, offsetting the pushrod and making contact with the guides even more likely.
Wait a minute. It's been a while since I've worked with this setup. Don't the pushrod guides maintain contact to keep the rocker centered?
That is my understanding, the guides keep the pushrods in place to keep the rockers centered. I do understand the concern about the pushrod length causing the contact pattern in the other axis, but I didn't get there yet. I trusted the 'bolt on parts' and just slapped it together. I did find the OEM bolts and rockers so I can eliminate all but the lifters if the noise persists.
Only if the rockers are causing the problem.
I think I found something, with your guidance. Can this make the noise? AND does this uncover that the pushrods are too short? Using the OEM rockers and bolts I was able to align the pushrod guide plates and then swap out one at a time to the adjustable studs without the plate moving. The valve side to side looks much better, but the front to back is obviously sus (or the other way around if you are looking in relation to the engine).
Attachment 135928
Attachment 135929
First picture is contact pattern at zero lash then second picture is total contact pattern as valve moves? Second picture definitely shows that the contact pattern is way off.
So you can fix the side to side misalignment for all rockers? Was it just the position of the guides?
The pushrod would have to be shorter to center the roller tip contact pattern because the rocker fulcrum is below the valve tip in height. How much, .025 .050, can't say. Looks like you need an adjustable pushrod length checker and test spring. Be careful with the length checker because the test spring might not be strong enough to compress the lifter. If that's the case, factor in how much the lifter should compress vs turns it takes to go from zero lash to full.
Also in the second picture it looks like the pushrod on the right is touching the clearance hole in the head.
The first and second are after removing the rocker having turned the engine over a few times. They appeared to show the same pattern when I eyeballed it.Quote:
Originally Posted by SiriusC1024
I did seem able to adjust the side to side on all on the driver's side, so I am assuming I can do so on the passenger side as well. It seemed to be the position of the guides. I made the (incorrect) assumption that they would align when bolted down during original assembly.
I will look into measuring the correct length pushrods and such. I know this needs to be done regardless, but do you think that could be the noise I (and the knock sensor) are hearing?
The rocker in that pic is loose, so the pushrod is just leaning around, but I will double check when I get back in there for sure!
I think setting alignment and contact pattern will fix it.
Imagine the pushrod being misaligned horizontally. As it goes up what was once clearance will now be a touch point. That's why the guide plates are slotted. Only allow for misalignment in one direction - along rocker rotation. Not across.
Contact pattern could cause noise, too. Worse, it'll break off a piece of the valve tip and wear out the roller tip axles.
I hope that is the issue. Reassuring to hear that this may be it. It will take me a bit to get this sorted because I don't have the tools for that yet! I was mostly an import mechanic and mostly stock factory stuff at that. Thanks again for all the help!
Also, the pushrods that came with the cam kit were about 1/16" longer than factory.... I figured they were just stronger due to the increase in valve spring pressure, but maybe that has something to do with the contact pattern. You mentioned that once I get a measurement for the one cylinder, it should be the same for the rest correct?
I'm just glad that I am able to help honestly. It was to the point of throwing guesses out there.
Do check clearance on the hole in the head. Account for deflection of the pushrod (bending) at higher rpm's. Needs to be a fair amount. Pretty sure those holes are typically machined slotted or clearanced with a die grinder for higher lift cams and bigger diameter pushrods.
Well, from what I am reading, another benefit of having the proper geometry is additional lift!
Haha true!
Ok, so I don't think I can get much better than this:
Attachment 136047
Attachment 136048
I think I am the 'victim' of some dumb luck here... Just for the hell of it, I tried the original pushrods since the new cam kit came with longer ones (assuming due to the new smaller base circle) and I needed shorter ones. I guess the decking and the base circle cancelled each other out??? I'll take whatever small favors I can get!
Just waiting confirmation from here that what I think is correct then I can button her back up and see what we have!
That's a good pattern. Just make sure the pushrods are up to the task of handling the extra load. Could always order a set of stronger ones that are stock length. Might go .025" shorter than factory length to get it perfect.
Pay attention that the guide plates are sized for the pushrod diameter. Also, no contact at any point of travel on the bottom of the guide plates. Only side to side on those.
Double check that the ball end of the pushrod matches the cup of the rocker! Maybe I'm seeing it wrong, but it looks different between the two. How's that going to be in the lifter cup, too? That could've been making noise and affecting oil pressure, too.
Left to right good I take it? Clearance on pushrod holes in the head? Can't quite tell without being there.
I have checkers and am going to shorten another 0.025 ( 7.600" and 8.550") and retest the pattern before ordering
The old and new along with the guide plates are all 3/8". I will double check clearance for plates and holes in heads.
The old and new pushrods were the same and I will check the bottom of the rockers when I get the checkers in there. Pretty sure it was the same.
I believe I was able to straighten out the left to right with the guide plates.
Sweet. I think this will be the fix.